Though all current Nokia phones run Windows Mobile, The Wall Street Journal is reporting that Nokia is planning to push out one last new phone before Microsoft takes over, and that phone will be running Android. Albeit, a heavily reskinned and modified version of Android, but Android nonetheless.
Based on earlier leaks, Nokia has been working on their own version of Android for at least a few months now, with photos leaking showing a heavily reskinned and basic-looking Android operating system that could be the footwork of what's going into this new Android device. It has been reported that the new phone will be a lower-end device to replace Nokia's Asha S40 systems. This has some weight behind it due to the fact that Windows Mobile is notorious for running poorly on low-end devices, while Android does quite well, and especially when you consider the earlier leaks that showed a stripped-down Android environment.
The phone is expected to be announced and unveiled at the Mobile World Congress event that starts the 24th of this month.